hexrd.material.symmetry module
- hexrd.material.symmetry.GeneratePGSYM(pgsym)[source]
@AUTHOR Saransh Singh, Lawrence Livermore National Lab, saransh1@llnl.gov @DATE 11/23/2020 SS 1.0 original @DETAIL. generate the point group symmetry given the point group symbol
- hexrd.material.symmetry.GeneratePGSym(SYM_SG)[source]
calculate the direct space point group symmetries from the space group symmetry. the direct point group symmetries are merely the space group symmetries with zero translation part. The reciprocal ones are calculated from the direct symmetries by using the metric tensors, but that is done in the unitcell class
- hexrd.material.symmetry.GeneratePGSym_Laue(SYM_PG_d)[source]
generate the laue group symmetry for the given set of point group symmetry matrices. this function just adds the inversion symmetry and goes through the group action to generate the entire laue group for the direct point point group matrices
- hexrd.material.symmetry.GenerateSGSym(sgnum, setting=0)[source]
get the generators for a space group using the generator string
- hexrd.material.symmetry.GeneratorString(sgnum)[source]
these rhombohedral space groups have a hexagonal setting with different symmetry matrices and generator strings 146: 231 148: 232 … and so on
- hexrd.material.symmetry.MakeGenerators_PGSYM(pggenstr)[source]
@AUTHOR Saransh Singh, Lawrence Livermore National Lab, saransh1@llnl.gov @DATE 11/23/2020 SS 1.0 original @DETAIL. these are the supporting routine to generate the ppint group symmetry
for any point group. this is needed for the coloring routines
- hexrd.material.symmetry.quatOfLaueGroup(tag)[source]
Generate quaternion representation for the specified Laue group.
USAGE:
qsym = quatOfLaueGroup(schoenfliesTag)
INPUTS:
1) schoenfliesTag 1 x 1, a case-insensitive string representing the Schoenflies symbol for the desired Laue group. The 14 available choices are:
Class Symbol n
Triclinic Ci (S2) 1 Monoclinic C2h 2 Orthorhombic D2h (Vh) 4 Tetragonal C4h 4
D4h 8
- Trigonal C3i (S6) 3
D3d 6
- Hexagonal C6h 6
D6h 12
- Cubic Th 12
Oh 24
OUTPUTS:
1) qsym is (4, n) the quaterions associated with each element of the chosen symmetry group having n elements (dep. on group – see INPUTS list above).
NOTES:
*) The conventions used for assigning a RHON basis, {x1, x2, x3}, to each point group are consistent with those published in Appendix B of [1].
REFERENCES:
[1] Nye, J. F., ``Physical Properties of Crystals: Their Representation by Tensors and Matrices’’, Oxford University Press, 1985. ISBN 0198511655